1. Field of the Invention
The invention pertains to an apparatus for the assembly of grommets on electrical cables or wires, having a drum adapted to be filled with grommets, and open on at least a front side, which is adapted to be driven about an axis inclined relative to a horizontal plane, having scoops or vanes arranged on the inside of the drum and having a conveyor guide rail extending into the drum which receives, during rotation of the drum, the grommets for the purpose of proper orientation, storage and further conveyance, wherein a discharge device, having an upwardly and downwardly movable centering mandrel, from which the first grommet in the conveyor or guide rail is always conveyed to a turning device.
2. Discussion of the Background of the Invention and Material Information
With apparatuses of the type noted above, grommets, which for example, are required for the moisture-proof passage or feed-through of electrical cables through the housing walls of electrical devices, can be economically pushed onto the cables.
In an apparatus of the above type and known from EP-A-0 534 106, the grommets are properly oriented in a buffer storage of the conveyor guide rail. Being aligned with the axis of a vertical bore of a first grommet in the buffer storage, a single cylinder, having an upwardly and downwardly movable mandrel, is arranged or located above the conveyor guide rail, and a pivotable assembly cylinder, having a grommet-receiving portion sitting on a piston rod thereof, is arranged below the conveyor guide rail, whereby the grommet, via the mandrel, is pushed through the vertical bore into the grommet-receiving portion or grommet-holding part and the assembly cylinder is pivoted in a horizontal position. Thereafter, pivotable gripper jaws surround the grommet-receiving portion and are moved, together with the piston rod, against the cable, whereby the grommet is pushed onto the cable. During this operation, the grommet bore is slightly expanded, via a supply of air under pressure, so as to ease the pushing of the grommet. With the use of this method, malfunctions can however occur, depending upon the flexibility, composition or sizing accuracy of the cable and/or the grommets.
A further grommet assembly apparatus is described in EP-A- 0 410 416, in which the grommets are mechanically expanded before being pushed onto an electrical cable. During this operation, a grommet that has been brought to an outlet position, is initially received on a mandrel and pushed up to a ring-shaped elastic abutment in a grommet-receiving portion. The mandrel is conically shaped so that, during its further movement, the grommet is expanded. The cylindrical portion of the mandrel carries a sleeve, which, during the further movement for the purpose of expansion, is positively moved with the mandrel and enters into the grommet bore. When the sleeve has reached the elastic abutment, the mandrel is pulled back, with the sleeve remaining at the noted position. Thereafter, the cable, at the already stripped end, is pushed from the other side of the grommet-receiving portion, through the ring-shaped abutment, onto the sleeve, which is then pulled back so that the grommet can clamp itself or contract onto the cable. Subsequently, the grommet-receiving portion opens so that the cable is released. The previously-described apparatus is quite complicated and expensively constructed, with the components, that are subject to wear, also being difficult to reach. In addition, the assembly time per grommet, which is influenced by the noted construction, is relatively long.